From: Matthijs Kooijman <matthijs@stdin.nl>
Date: Tue, 3 Nov 2009 14:40:39 +0000 (+0100)
Subject: Add and use clip_index and wrap_index helpers.
X-Git-Url: https://git.stderr.nl/gitweb?a=commitdiff_plain;h=80501ced4dd4ccb5567283f16b49327140474fdf;p=matthijs%2Fupstream%2Fmobilegtd.git

Add and use clip_index and wrap_index helpers.
---

diff --git a/src/gui/gui.py b/src/gui/gui.py
index 94ade06..a981b61 100644
--- a/src/gui/gui.py
+++ b/src/gui/gui.py
@@ -217,7 +217,7 @@ class ListView(View):
         we'll have to adjust the index with the direction of the
         keypress (-1 for up, +1 for down).
         """
-        self.current_index = (self.selected_index() + dir) % len(self.items())
+        self.current_index = self.wrap_index(self.selected_index() + dir)
         self.index_changed()
         self.current_index = None
 
@@ -258,6 +258,24 @@ class ListView(View):
         else:
             return self.view.current()
 
+    def clip_index(self, index):
+        """
+        Make sure the given index fits within the bounds of this
+        list. If it doesn't, clip it off at the ends of the list (e.g,
+        -1 becomes 0).
+        """
+        max_index = len(self.items_cache) - 1
+        return max (0, min(max_index, index))
+
+    def wrap_index(self, index):
+        """
+        Make sure the given index fits within the bounds of this
+        list. If it doesn't, wrap it around (e.g., -1 becomes 5 in a
+        6-element list).
+        """
+        count = len(self.items_cache)
+        return index % count
+    
 class WidgetBasedListView(ListView):
     def __init__(self):
         self.binding_map = {}